PHP+redis实现的购物车单例类示例

<?php
/**
 * 购物车单例类
 *
 * @author ying
 * @param void
 * @return void
 */
class cartsingleton
{
  //定义一个静态的私有变量
  static private $_instance=null;
  private $redis=null;
  //私有化的构造方法
  private final function __construct()
  {
    //实例化
    $this->redis=new redis();
    $this->redis->connect('127.0.0.1',6379);
  }
  //私有化的克隆方法
  private function __clone()
  {
  }
  //公有的静态方法
  static public function getinstance()
  {
    if(!(self::$_instance instanceof self)){
      self::$_instance = new cartsingleton();
    }
    return self::$_instance;
  }
  /**
   * 加入购物车
   *
   * @author ying
   * @param userid goodsname goodsid 用户id 商品名称 商品id
   * @return int
   */
   public function addcart($userid,$goodsname,$goodsid)
   {
     $hashkey="user_".$userid; //hash键名
     $key=$goodsid."_".$goodsname;//键名
     //加入
     return $this->redis->hincrby($hashkey,$key,1);
   }
  /**
   * 单删
   *
   * @author ying
   * @param userid goodsid
   * @return
   */
  public function cartdelone($userid,$goodsid)
  {
    $hashkey="user_".$userid; //hash键名
    $key=$goodsid;//键名
    //删除
    return $this->redis->hdel($hashkey,$key);
  }
  /**
   * 清空购物车
   *
   * @author ying
   * @param userid
   * @return void
   */
  public function cartdelall($userid)
  {
    $hashkey="user_".$userid; //hash键名
    //删除
    return $this->redis->del($hashkey);
  }
  /**
   * 购物车列表
   *
   * @author ying
   * @param userid
   * @return void
   */
  public function cartlist($userid)
  {
    $hashkey="user_".$userid; //hash键名
    //查询数据
    return $this->redis->hgetall($hashkey);
  }
}
//实例化类
$obj=cartsingleton::getinstance();